Control valve device



Patented Aug. 19, 1947 CONTROL VALVE DEVICE Roy R. Stevens, ForestHills, and Harry M. Linhart, Pitcairn, Pa., assgnors to The WestinghouseAir Brake Company, Wilmcrding, Pa., a corporation of PennsylvaniaApplication June 22, 1944, Serial No. 541,597

valve device is usually controlled by a manually operative controllerand mechanism interlocked with the engines reversing gear, so that inreversing the engine, starting air will not be supplied to the engine bythe relay valve device until after the reversing gear has been actuatedto condition the engine for operation in the selected direction. Astructure of this general type is fully disclosed in the copendingapplication of Roy R. Stevens and Erik G. Erson, Serial No. 520,256,filed J anuary 29, 1944 which issued as Patent No. 2,395,202 on February19, 1946.

One object of the invention is the provision ol 'an improved fluidpressure actuated relay valve device particularly adapted, but notlimited, for controlling the supply of starting air to a Diesel engine.-

Another object of the invention is the provision of a relay valve devicesuch as just defined embodying fluid pressure controlled means foreffecting operation thereof in case the supply of actuating iiuidpressure, above mentioned, should for any reason fail.

Other objects and advantages will be apparent from the following moredetailed description of the invention.

In the accompanying drawing; the single figure is a longitudinalsectional View .of a relay valve device constructed in accordance withthe invention.

As shown in the drawing, the relay valve device comprises a body Ihaving a bore closed by a cover 2, and slidably mounted in said bore isan inverted cup shaped poppet type fluid pressure supply 'valve 3. Aring-shaped seat 4 is provided in the body for sealing engagement by thehead of valve 3 to close communication between av chamber 5 at one sideof the seat and a chamberv 6 at the opposite side of the seat. vThechamber 3 Claims. (Cl. 137-144) I5 is connected to a uid pressure supplypipe 'I which may constitute a source of high pressure starting air fora Diesel engine, while chamber yIi is open to a pipe 8 which may lead toair starting mechanism of said engine. With valve 3 disengaged from seat4 it will be apparent that uid under pressure will be permitted to owfrom pipe I to pipe l8, while with said valve closed against said seat,the supply of fluid under pressure to Pipe 8 will be cut off.

Between cover 2 and valve 3 is a chamber I9 which is constantly openthrough a relatively small port I0 in said valve to chamber 5 .and theiiuid pressure supply pipe .1. The head of valve 3 is provided with anaxial bore connecting chamber 9 to chamber 6 and containing a flutedstem II of a poppet valve I2 contained in chamber 9 and adapted toengage a seat provided on said head around the adjacent end -of saidbore. Opening of valve I2 will permit flow of fluid from chamber 9 tochamber 6, while closing of said valve will prevent such flow. 4

In chamber 9 are disposed two concentrically arranged coil bias springsI3 and I4 acting on valves 3 and I2, respectively, and supported on afollower I5 which in turn is supported on a pin I6 secured in cover 2.Both of these springs are under pressure so as to urge the respectivevalves in their seats. With valve I2 closed, chamber 9 and this pressureacting in conjunction with the pressure of springs I3 and I4 will closevalve 3 against opposing pressure of uid in chamber 6.

duce the seating force on the valve 3 to facilitate e opening thereof,which will be later described.

The stem II of'valve -I2 extends beyond the valve 3 into chamber 6 aslight distance, .and in the adjacent 'face of valve 3 and at eitherside of said stem are slots I 'I which are'A provided for rea sons whichwill be later described.

will become charged by way of port IU with uid at the same pressure assupplied to chamber 5 through pipe l,

of which is mounted a cover I8 and in which there is slidably mounted apiston I9 in coaxial relation to the valve 3. The piston I9 has at oneside a pressure chamber 20 which is open through a choke 2| to a controlpipe 22 which may constitute the usual starting control pipe for aDiesel engine. The piston 9 has at the opposite side a chamber 23 whichmay be open directly to the atmosphere as shown in the drawing.

The piston I9 is provided with a stem 24 projecting therefrom throughchamber 23 and through a bushing 25 provided in a wall 26, separatingsaid chamber from chamber 6. and into the latter chamber in operatingalignment with valve 3 and stem II of valve I2. The piston stem 24 hasadjacent the piston I9 a release valve 21 for sealing engagement with aseat 28 provided on the adjacent end of bushing 25. Adjacent valve 21,the stem 24 is provided with a cylindrical portion 29 adapted toslidably enter and substantially close the bore in bushing 25, while theremaining portion 30 of the stem is iluted. With piston i9 in theposition shown in the drawing, the uted portion 30 of the stem extendsfrom chamber 6 into chamber 23 to allow release of iluid under pressurefrom chamber 6 to chamber 23 and to atmosphere.

In the end of piston stem 24 is a striker button 3| provided forcontacting the stem II of valve I2 and for also engaging valve 3. Thelength of the cylindrical portion 29 of the pis- .ton stem 24is such asto be disposed in bushing 25 to close communication between chambers 6and 23 past the fluted portion 30 of said stem with the striker button'3| in substantial contact .with valve stem Il, when the valves I2 and 3are both seated, as shown in the drawing.

A coil spring 32 disposed in chamber 23 has one end supported on thebody wall 26. The other end bears against piston I9. This spring isunder pressure for urging the pistonk I9 to the position shown in thedrawing and dei-ined by contact with cover I8.

The cover I8 has a bore open to chamber 20 in coaxial relation withpiston I9 and containing a piston 33. One side of piston 33 isthussubject to pressure of fluid in chamber 20 and is arranged for contactwith piston i9 While at the opposite side of said piston is a pressurechamber 34 open to a. control pipe 35. The cover I 8 is provided withstops 36 extending into chamber 34 for contact with piston 33 to limitmovement thereof in a direction away from piston |9. A ring seal 31 iscarried in an annular groove provided in piston 33 and has a sealingcontact with the .wall of the bore in which the piston operates toprevent leakage of fluid under pressure between chambers 20 and 34.

The pipe 35 is connected to a manually operable valve device 38 to whichis also connected a pipe 39 from the starting air supply pipe 1. Thevalve device 38 may, for the purpose of illustration, be of a typecomprising a casing containing a rotary plug valve 40 to which isconnected a manually operable handle 4| for turning said valve. Thevalve 40 and handle 4| have a normal position as shown in the drawingand are movable from this position to an engine starting position inwhich the handle will be located in a position such as indicated by adot and dash line 42.

The plug valve 40 is provided with a T-shaped passage 43 which in thenormal position of said valve opens pipe 35 to a vent port 44 leading toatmosphere, the connection with pipe 39 being lapped or closed in thisposition of said valve.

In the engine starting position of valve 40 the vent port I44 is lappedand port 43 opens corri-v Vber 34 to atmosphere. With the parts thusconditioned if`it is desired to supply starting air to the engine, fluidunder pressure will be supplied to pipe 22 by the conventional means(not shown) and thence through choke 2| to chamber 20.. When thepressure of fluid in chamber 20 is thus increased suillciently toovercome the opposing force of spring 32, said piston will move awayfrom cover I8 in the direction of valve 3 and stem II of valve I2. Atsubstantially the time or just prior to the button 3| in the end of thepiston stem 30 engaging the valve stem II, the cylindrical portion 29 ofthe piston stem will enter bushing 25 to close the fluid releasecommunication from chamber 6. After the button 3| engages the valve stemII, further movement of piston I9 will then unseat valve I2 to releasefluid under pressure from chamber 9 to chamber 6 for reducing thepressure of fluid in chamber 9 as above described. The valve I2 willthus be moved relative to valve 3 until the button 3| engages valve 3 atopposite sides of slots I1 provided in the head of said valve, whereuponfurther movement of piston 20 by fluid under pressure will move thesupply valve 3 away from its seat until the release valve 21 engages itsseat 28. With the supply valve 3 thus open, iluid under pressure willflow from pipe 1 to pipe 8 to effect the starting of the engine.

The slots I1 are provided to maintain open the venting communicationfrom chamber 9 past valve I2 to chamber 6 with the button 3| in contactwith the supply valve 3 so as to thereby maintain the differential influid pressures on the supply valve 3 at a relatively low degree.Engagement of the release valve 21 with seat 28 is provided to preventany leakage of starting air from chamber 6 with the valve 3 open, whilethe cylindrical portion 29 of the piston stem minimizes suchleakageduring opening of the supply valve 3 as well as during closing whichwill now be described.

When it is desired to cut of! the supply of starting air to pipe 8,fluid under pressure will be' released from pipe 22 and piston chamber20 whereupon the pressure of spring 32 will return piston 20 to itsnormal position shown in the drawing. As the piston 20 is thus movedtoward its normal position the supply valve 3 is seated by spring I3followed by seating of valve I2 by spring I4 so as to prevent furthersupply of fluid under pressure from pipe 1 to pipe 8. At substantiallythe same time as valve I2 is seated, the

ing air, this increase in pressure in chamber 23 may be of such a degreeas to tend to slam the piston I9 against the cover I8. Such slamming ishowever prevented by choke 2I which so restricts the release vof fluidunder pressure from chamber as to create an air cushion upon suddenmovement of the piston to thus absorb the in ,ertia of the piston andprevent its moving against the cover I8 with damaging force.

Now if forany reason there is no fluid pressure available for supply topipe 22 to control the 'operation of the relay valve device as abovedescribed, and under which condition the pressure of fluid in chamber 20will be substantially that of the atmosphere, the relay valve device maybe operated to supply fluid under pressure to pipe 8 by turning plugvalve and handle 4I from the position shown in the drawing to the enginestarting position indicated by line 42. In this engine startingpositionl fluid under pressure will be supplied from the air supply pipe1 to pipe 35 and thence to chamber 34 above the piston 33. The piston 33will then move downwardly and actuate the piston I9 to cause fluid underpressure to be supplied tothe starting pipe 8 in the same manner as whenpiston I 9 is operated by fluid under pressure supplied to chamber asabove described. When the operator desires to cut off the supply ofengine starting air to pipe 8 and to release the uid under pressure fromsaid pipe, he will operate handle 4I to return valve 40'to the positionshown in the drawing for releasing fluid under pressurefrom pistonchamber 34. Pistons I9 and 33 will then be returned to their normalpositions shown in the drawing by spring 32, and the relay valve devicewill release fluid under pressure from pipe 8 in the same manner asabove described.

In the control of Diesel engines the pressure of the engine starting airsuch as provided in pipe 1, may be several times, for instance three,the pressure of controlling fluid available for supply to the enginestarting control pipe 22. Since the piston 33 is operated by thestarting air, its area need therefore be only a fraction such asone-third, of the area of piston I9 to obtain the same force for openingthe supply valve 3.

Having now described our invention, what we claim as new and desire tosecure by Letters Patent, is:

1. A relay valve device comprising a casing, a supply valve in saidcasing operable to supply lluid under pressure to a first chamber, apiston in said casing subject to opposing pressures of iluid in secondand third chambers, said third' chamber being open to atmosphere, a stemcarried by said piston and operable by said piston upon supply of fluidunder pressure to said second chamber to actuate said supply Valve tosupply uid under pressure to said first chamber, a release valve on saidstem, a seat in said casing arranged to be engaged by said release valveto 4close a fluid pressure release communication said supply valve tocut olf the supply of fluid under pressure to said first chamber, saidrelease control means opening said communication upon release of fluidunder pressure from said piston subsequent to operation of said supplyvalve to cut off the supply of fluid under pressure to said rst chamber,and flow restricting means arranged to restrict release of fluid underpressure from said piston.

2. A relay valve device comprising a casing, a supply valve in saidcasing operable to supply uid under pressure to a chamber, a stemslidably mounted in a bore in said casing operable upon movement in onedirection to open said supply valve and operable upon movement in theopposite direction to permit closing of said supply valve, said casinghaving a valve seat around said bore, a release valve on said stemarranged to contact said seat with said supply valve open and todisengage said seat with said supply valve closed, said stem also havinga cylindrical portion adjacent said release valve adapted to slidablyenter said bore to close communication through said bore ahead ofopening said supply valve and movable out of said bore after closing ofsaid supply valve, and said stem. comprising another portion projectingfrom said cylindrical portion through said bore for engagement with saidsupply valve and so constructed. as'to allow release of fluid underpressure from said chamber through said bore, a piston connected to saidstem and operable by iluid under pressure to actuate said' stem to opensaid supply valve, and means operable upon release of fluid underpressure on said piston to actuate same to move the cylindrical portionof said stem out of said bore.

,3. A relay valve device comprising a casing having a first chambersupplied with fluid under pressure and having a second chamber, a poppettype supply valve in said casing having an open position for supplyingfluid under pressure from said flrst chamber to said second chamber anda closed position for cutting off the supply of fluid under pressure tosaid second chamber, said poppet valve being subject to pressure offluid in a third chamber which urges it to its closed position, a portarranged to supply fluid under pressure from said first chamber to saidthird chamber, a pilot valve having a fluid flow capacity exceeding thatof said port 'and operable to release fluid under pressure from saidthird chamber to said second chamber, said pilot valve being disposedaxially in said supply valve, a stem slidably mounted in a bore in saidcasing in coaxial relation to said valves and operable upon movement inthe direction of said valves to rst open said pilot valve and then saidsupply valve and operable upon movement in the opposite direction topermit closing iirst of said supply valve and then of said pilot valve,means operable to close said valves upon movement of said stem in saidopposite direction, said casing having a valve seat around said stem, arelease valve formed on said stem to engage said seat upon opening ofsaid supply valve, said stem comprising a cylindrical portion arranged'to enter and to have sliding contact with the wall of said bore ahead ofopening of said pilot valve and movable out of said bore upon closing ofsaid pilot valve, said stem further comprising a portion projecting fromsaid cylindrical portion through said bore for operating said pilot andsupply valves and so constructed as to permit release of fluid underpressure from said second chamber, a piston connected to said stem andoperable by fluid under pressure supplied to a fourth chamber to movesaid stem in the direction of said supply valve, means operable uponrelease of uid under pressure from said fourth chamber to effectmovement'l of said piston and stem in the said opposite direction, andmeans arranged to restrict release of fluid under pressure from saidfourth chamber.

ROY R. STEVENS.

HARRY M. LINHART.

REFERENCES CITED 'Ihe following references are of record in the ille ofthis patent' Number

